#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>

int main()
{
  printf("output once\n");
  int ret=fork();

  printf("output twice : pid: %d, ppid: %d, ret = %d\n", getpid(), getppid(), ret);
  sleep(1);
  return 0;

}
